This invention relates to antennas and more particularly to an improved antenna aperture polarizer.
One type of polarizer to which this invention relates constitutes a cover placed in front of the aperture of an antenna such as a pyramidal horn for converting linearly polarized waves propagating in the horn to circularly polarized waves on the other side of the polarizer. Such a polarizer consists of a plurality of spaced arrays of conductive traces extending across the horn aperture generally at an acute angle to the plane of polarization of the horn. A polarizer of this type is described in U.S. Pat. No. 3,754,271.
A difficulty encountered with prior antenna polarizers is the buildup of a static electrical charge on the ungrounded arrays which tends to cause arcing between the array and metallic parts of the antenna. Such arcing is undesirable because it adversely affects the antenna radiation pattern. Attempts to solve this problem have involved grounding the arrays with shorting wires soldered to the respective arrays and to ground. This construction has been unsatisfactory, however, because of unreliability of the resulting joints, the difficulty in making them, and the electric field perturbation they tend to cause.
This invention is directed to a solution to this problem.